A new study published in the Proceedings of the National Academy of Sciences
by a University of Maryland-led team has opened the door to seeing how cells respond to physical signals.

“We elucidated a cell’s sense of touch,” said Wolfgang Losert, a professor of physics at UMD and a team leader of the study. “We think how cells sense the physical environment may be quite distinct from how they sense the chemical environment. This may help us develop new treatment options for conditions that involve altered physical cellular environments, such as tumors, immune disease and wound healing.”

A major difference between chemical signals, which are more fully understood, and physical signals is size. Chemical signals are 100,000 times smaller than the width of a human hair. Physical cues are the heavyweights in the ring.

“We’re really answering a kind of long-standing mystery of how cells react to cues in their environment that are on a physical rather than chemical-size scale,” said paper co-author John T. Fourkas, a professor in UMD’s Department of Chemistry and Biochemistry, who, like Losert has a joint appointment in the Institute for Physical Science and Technology.

The Multidisciplinary University Research Initiative, funded by the Air Force Office of Scientific Research, includes researchers in physics, chemistry, biology, bioengineering and dermatology from UMD and several other institutions. The team studied the major players in a cell’s interaction with its physical environment: the cytoskeleton, a network of proteins that surround a cell and acts as a direct sensor of the physical environment; actin, the protein that keeps cells connected; and the cell’s signaling pathway. They found that the networks that guide cell migration are upstream for chemical sensing and downstream for physical, topographic sensing; and that actin is the direct sensor for both types of signals.